This study establishes a new item bank for self-efficacy for the PROMIS project. Self-efficacy is defined as an individual's perception of their ability to successfully perform certain tasks or behaviors, or more specifically, as the belief that one can carry out a behavior to achieve a desired goal related to one's health. Our study will focus upon self-efficacy for self-management of chronic medical conditions. The significance of self-efficacy is based on two main features: 1) self-efficacy is a pivotal mediator of human behavior and 2) self-efficacy has been shown to be modifiable by interventions that foster self-management skills. Successful adjustment and good outcomes in chronic disorders depend upon the ability to adopt and master new behaviors. A multi-step process will be employed to develop the item pool, with contributions from experts in the field of self-efficacy, clinicians, and patients. Validation studies of the self-efficacy item pool will be conducted in five chronic neurologic disorders: epilepsy, multiple sclerosis, Parkinson's disease, peripheral neuropathy, and stroke. We will investigate the effects of diverse clinical features of these disorders on self-efficacy. Based on patient-reported data, we will also assess the magnitude of a clinically important difference and the responsiveness to change of the new self-efficacy measures. Relevance Developing the PROMIS self-efficacy item bank will raise awareness and promote clinical research in self-efficacy in many chronic disorders, thereby pushing this important field forward. The ultimate goal of these studies is to provide information that will aid in the development of interventions to improve self-efficacy, promote self-management and reduce and delay disability. PUBLIC HEALTH RELEVANCE: Developing the PROMIS self-efficacy item bank will raise awareness and promote clinical research in self-efficacy in many chronic disorders, thereby pushing this important field forward. The ultimate goal of these studies is to provide information that will aid in the development of interventions to improve self-efficacy, promote self-management and reduce and delay disability.